Maserati Coupe 4200 space saver question

Phil the Brit

Member
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1,499
Just noticed that my space saver tyre/wheel in the boot of my Coupe 4200 is a 185/60/17 93P Vreidestein but the car runs on 18 inch wheels. Is it correct part for the car?
Many thanks in advance.
Phil
 

BL330

Member
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1,121
Yep that's what mine is.
Had a moment to check before the start of the race.
 

safrane

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16,749
Anyone know where to get new tyres for these?

All the sets I have looked at have cracked sides where the fold crease is... not paying a princely sum for a part that is not fit for purpose.
 

Phil the Brit

Member
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1,499
Interesting, you just made me look at mine in great detail. It seems perfect. Do they make space savers with a different material?
 

Phil the Brit

Member
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1,499
Yep that's what mine is.
Had a moment to check before the start of the race.

Thanks for the reply. Seems unusual to have a different wheel size for a space saver. The space saver has a higher profile so I guess this is what makes it OK for use with 18 inch wheels. Anyway, many thanks for the confirmation that even though my wheels are 18 inch the space saver is correct at 17 inch. The wheel kit came as a kit from new so I thought it would be right but doubts creep in...........!
 

mjheathcote

Centenary Club
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9,033
Thanks for the reply. Seems unusual to have a different wheel size for a space saver. The space saver has a higher profile so I guess this is what makes it OK for use with 18 inch wheels. Anyway, many thanks for the confirmation that even though my wheels are 18 inch the space saver is correct at 17 inch. The wheel kit came as a kit from new so I thought it would be right but doubts creep in...........!

Actually most space savers are of a smaller diameter due to the narrower tyre and higher profile, usually by an inch, any more and they would be brake disc/caliper clearance problems.
 

safrane

Member
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16,749
Interesting, you just made me look at mine in great detail. It seems perfect. Do they make space savers with a different material?
I have seen a Japanese one that can be adapted but the tyre was very perished.

Also one for a Maser, that too was starting to split.

I guess like all tyres they age and spoil.

Want one for mine but has to be 100% reliable otherwise rather pointless.
 

gstroe

Junior Member
Messages
47
Hey Phil, welcome to the vredestein space saver nightmare. Tire is not available on its own, only sold as a package mounted on the rim and costs upwards of 1,000 dollars. I’ve tried all I could for the past 3 or 4 years and came empty handed. If you find anything I can tell you there will be lots of interested buyers, myself included
 

spkennyuk

Member
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5,932
Seems there are only around 20 or so different space saver tyre sizes available. The road hero kits are the same limited number of tyres mixed across different hub sizes.

Given the age of the kits still out there for the 4200 and GS the tyres on the space saver kits are well beyond the tyres being in a safe usable condition imho.

I have no idea with the hump floor how much extra space can be accomodated. But to come up with a solution you need to start with the tyre sizes available and work back.

This is just an example but worth a bit more research.

To get the rolling diameter as close as possible you either have to go up a rim size with a lower profile tyre or down a size with a higher profile. You need to keep the rolling diameter within 2.5% so that it doesnt throw the speedo out, gear ratios and i would suspect possible traction control issues.

In this case i have just gone down a size as a quick example. In the picture below i have taken a space saver tyre size that is available.

72780

The space saver tyre size used is 185x65x16 as you can see the rolling diameter is 0.8% difference.

The next issue would be having custom wheels made that are 16 inch with enough clearance to clear the hubs.

Your talking custom built if its possible but as a group buy 4 at a time for example i can see it costing around £250 for the wheel plus the cost of the tyre which is around £70 for the tyre.

If you went up a size to an 18 inch rim then the tyre widths available drop.

The nearest i can find is 145 x 70 x 18 which is made by bridgestone for £60 a tyre. Hub clearance would be much easier with an 18 inch rim. The picture below shows the overall difference in diameter would be inside the 2.5% allowed.

72781

Im sure somebody with greater knowledge than me would be able to suggest possible custom wheel makers that could make a reasonable priced set of custom wheels for the purpose. If they are made from alloy then they can be cut from billet and be lighter than a steel alternative that just doesnt exist in the right size offset and stud configuration that i can find at the moment.
 
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safrane

Member
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16,749
You need a tyre that 'folds' along the side wall or it (a 18" wheel), will not fit in the well.